Re: [PATCH v8 05/26] drm/xe: Modify xe_force_wake_put to handle _get returned mask

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 08.10.2024 09:10, Himal Prasad Ghimiray wrote:
> Instead of calling xe_force_wake_put on all domains that were input to
> xe_force_wake_get, call _put only on the domains whose reference counts
> were successfully incremented by the _get call. Since the return value
> of _get can be a mask that does not match any specific value in the enum
> xe_force_wake_domains, change the input parameter of _put to unsigned int.
> 
> v3
> - Move WARN to this patch (Badal)
> - use xe_gt_WARN instead of XE_WARN (Michal)
> - Stop using xe_force_wake_domains for non enum values.
> - Remove kernel-doc from this patch (Badal)
> 
> -v5
> - Fix global awake_domain
> 
> -v6
> - put all initialized domains in case of FORCEWAKE_ALL.
> - Modify ret variable name (Michal)
> - Modify input var name (Michal)
> - Modify commit message and warn (Badal)
> 
> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Badal Nilawar <badal.nilawar@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Cc: Nirmoy Das <nirmoy.das@intel.com>
> Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_force_wake.c | 28 +++++++++++++++++++++-------
>  drivers/gpu/drm/xe/xe_force_wake.h |  2 +-
>  2 files changed, 22 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_force_wake.c b/drivers/gpu/drm/xe/xe_force_wake.c
> index bfba276c48ac..7ff2588a8c47 100644
> --- a/drivers/gpu/drm/xe/xe_force_wake.c
> +++ b/drivers/gpu/drm/xe/xe_force_wake.c
> @@ -213,26 +213,40 @@ unsigned int xe_force_wake_get(struct xe_force_wake *fw,
>  }
>  
>  int xe_force_wake_put(struct xe_force_wake *fw,
> -		      enum xe_force_wake_domains domains)
> +		      unsigned int fw_ref)
>  {
>  	struct xe_gt *gt = fw->gt;
>  	struct xe_force_wake_domain *domain;
> -	enum xe_force_wake_domains tmp, sleep = 0;
> +	unsigned int tmp, sleep = 0;
>  	unsigned long flags;
> -	int ret = 0;
> +	int ack_fail = 0;
> +
> +	/*
> +	 * Avoid unnecessary lock and unlock when the function is called
> +	 * in error path of individual domains.
> +	 */
> +	if (!fw_ref)
> +		return 0;
> +
> +	if (fw_ref == XE_FORCEWAKE_ALL)
> +		fw_ref = fw->initialized_domains;
>  
>  	spin_lock_irqsave(&fw->lock, flags);
> -	for_each_fw_domain_masked(domain, domains, fw, tmp) {
> +	for_each_fw_domain_masked(domain, fw_ref, fw, tmp) {
>  		if (!--domain->ref) {

shouldn't we assert that ref is non zero?

but otherwise LGTM so,

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>

>  			sleep |= BIT(domain->id);
>  			domain_sleep(gt, domain);
>  		}
>  	}
>  	for_each_fw_domain_masked(domain, sleep, fw, tmp) {
> -		ret |= domain_sleep_wait(gt, domain);
> +		if (domain_sleep_wait(gt, domain) == 0)
> +			fw->awake_domains &= ~BIT(domain->id);
> +		else
> +			ack_fail |= BIT(domain->id);
>  	}
> -	fw->awake_domains &= ~sleep;
>  	spin_unlock_irqrestore(&fw->lock, flags);
>  
> -	return ret;
> +	xe_gt_WARN(gt, ack_fail, "Forcewake domain%s %#x failed to acknowledge sleep request\n",
> +		   str_plural(hweight_long(ack_fail)), ack_fail);
> +	return ack_fail;
>  }
> diff --git a/drivers/gpu/drm/xe/xe_force_wake.h b/drivers/gpu/drm/xe/xe_force_wake.h
> index 75fa1a19797c..f0b27dbe7581 100644
> --- a/drivers/gpu/drm/xe/xe_force_wake.h
> +++ b/drivers/gpu/drm/xe/xe_force_wake.h
> @@ -18,7 +18,7 @@ void xe_force_wake_init_engines(struct xe_gt *gt,
>  unsigned int xe_force_wake_get(struct xe_force_wake *fw,
>  			       enum xe_force_wake_domains domains);
>  int xe_force_wake_put(struct xe_force_wake *fw,
> -		      enum xe_force_wake_domains domains);
> +		      unsigned int fw_ref);
>  
>  static inline int
>  xe_force_wake_ref(struct xe_force_wake *fw,